KR20010076133A - Ultra-high-temperature heat treatment apparatus - Google Patents

Abstract

PURPOSE: To reduce repairing costs by replacing the heater of an ultra high- temperature heat-treating device by a new one in single units and to reduce the reaction with a furnace material and the shrinkage of the furnace material, by fixing only a power introduction part, without fixing the heat generation part of the heater directly. CONSTITUTION: In an electric furnace B for composing an ultra high-temperature heat-treating device A, a heater 1 that can be replaced by a new one in single units is fitted to an inner wall surface 3 of a heat-insulating material 2 in the furnace without adhesion. Also, only a power introduction part is fixed and fitted, without fixing a heat generation part 4 for composing the heater 1 that can be replaced by a new one in single units, without gluing to the inner wall surface 3 of the heat-insulating material 2 in the furnace.

Description

Ultra High Temperature Heat Treatment Equipment {ULTRA-HIGH-TEMPERATURE HEAT TREATMENT APPARATUS}

The present invention relates to an ultra high temperature heat treatment apparatus.

BACKGROUND ART An ultra high temperature heat treatment apparatus that has an electric furnace and heat-treats a wafer or the like is known. An electric furnace of a conventional heat treatment apparatus has a heater composed of a single integral heater element, and the heater element is installed in a spiral shape or a half folded shape on the inner wall surface of the heat insulating material while fixing the heat generating portion directly to the heat insulating material of the electric furnace. According to such an integrated heater structure, if a part of the heater element is damaged, the maintenance cost is significantly increased because the entire heater element needs to be replaced.

The conventional heat treatment apparatus includes a water-cooled metal manifold and a SiC / CVD-SiC furnace tube installed on the upper side to receive a wafer, and the like. O-rings are inserted to prevent intrusion of contaminants and the like. According to such a configuration, the temperature cracking field of the core tube cannot be lengthened, and the thermal shock applied to the core tube is large.

In addition, the conventional heat treatment apparatus is arranged to block the high temperature heat from the core tube, but because of this, only the SiC buffer is used, so that the thermal conductivity under the core tube is large, which is expensive to prevent heat conduction.

In the conventional heat treatment apparatus, a flange that moves up and down relative to the manifold is disposed. In order to shield between the manifold and the flange, an O-ring was inserted into a tapered groove (typically a dovetail groove) formed in the flat portion on the flange side. O-rings, however, sometimes stuck to the manifolds due to high temperature heat and were separated from the tapered grooves of the flange.

In addition, the conventional heat treatment apparatus is provided with a separation mechanism for accommodating the wafer from the holder while accommodating the wafer in the ring-shaped holder, which is configured to push the wafer into the holder. However, the workability of the separation mechanism was not good.

One object of the present invention is to provide an ultra-high temperature heat treatment apparatus that can significantly reduce the maintenance cost of the heater to be able to independently exchange a plurality of heater elements constituting the heater of the electric furnace. Preferably, the heat treatment apparatus suppresses the reaction between the heat generating portion of each heater element and the heat insulator constituting the furnace material, and reduces the shrinkage of the heat insulator, thereby extending the life of the electric furnace.

Another object of the present invention is to provide an ultra high temperature heat treatment apparatus capable of arranging a junction between a furnace tube and a manifold in a high temperature environment and extending the temperature cracking field. Preferably, the heat treatment apparatus shields the junction portion by exhausting through the slit formed on the upper surface of the manifold and reduces metal contamination.

It is another object of the present invention to provide an ultra high temperature heat treatment apparatus which can reduce the heat conduction in a core tube by heat insulation treatment and can perform the cooling of the buffer installation part of a heat insulation device simply and at low cost.

Another object of the present invention is to provide an ultra-high temperature heat treatment apparatus that can be secured by preventing the O-ring disposed between the manifold and the flange constituting the pollution prevention device to be detachable.

Another object of the present invention is to provide an ultra-high temperature heat treatment apparatus which significantly improves workability by simply separating a wafer and preferably a ring-shaped holder for fixing the wafer.

The ultra high temperature heat treatment apparatus according to one aspect of the present invention includes an electric furnace including a heater consisting of a plurality of heater elements disposed independently of each other and interchangeably, and each heater element does not adhere to the inner wall surface of the electric furnace insulation material. It is characterized in that the arrangement.

According to the heat treatment apparatus of the present invention, it is possible to replace the heater elements of the electric heater by one unit, which can significantly reduce the manufacturing cost and maintenance cost of the heater.

Preferably, each said heater element is characterized by having a heat generating portion disposed along the inner wall surface of the heat insulating material and not in close contact with the inner wall surface, and an attachment portion fixed to the heat insulating material.

According to this suitable aspect, reaction of the heat generating part of each heater element and a heat insulating material, and shrinkage of a heat insulating material can be reduced, and the heat generating operation of a heater element can be performed stably at high temperature. In addition, since the heat generating portion of the heater element is not mechanically constrained, durability deterioration due to thermal strain stress does not occur, thereby extending the life of the heater.

The ultra-high temperature heat treatment apparatus according to another aspect of the present invention is characterized by having a core core, preferably a porous core SiC / CVD-SiC core core, and a quartz manifold provided below the core core.

According to the ultra-high temperature heat treatment apparatus of the present invention, the temperature core of the core tube can be lengthened by providing a quartz manifold below the core tube, preferably the porous core SiC / CVD-SiC tube. The thermal shock to the SiC core core tube can also be alleviated.

Preferably, a slit portion is arranged on an upper surface of the quartz manifold joined to the furnace core tube, and a vacuum exhaust system is connected to the slit portion.

According to this preferred embodiment, the intermediate surface can be vented through a slit portion disposed at the joint surface of the furnace core tube and the quartz manifold and connected to the vacuum exhaust system, thereby shielding the joint surface. In particular, when a SiC / CVD-SiC core core tube is used in combination with a quartz manifold connected to the exhaust system, metal contamination can be reduced.

The ultra-high temperature heat treatment apparatus according to another aspect of the present invention includes a core core, preferably a porous core core made of SiC / CVD-SiC, and a heat insulator fitted into the core tube to block heat conducted from the core tube. The apparatus is characterized in that it comprises a SiC buffer and a quartz buffer provided below it.

According to the ultra-high temperature heat treatment apparatus of the present invention, the heat conduction from the low core tube, preferably the porous SiC / CVD-SiC low core tube, can be reduced by the heat insulating device, and the cooling of the buffer installation portion of the heat insulating device can be easily performed at low cost. Can be.

The ultra-high temperature heat treatment apparatus according to another aspect of the present invention includes a core core, preferably a porous core core made of SiC / CVD-SiC, and a pollution prevention means installed below the core tube to prevent contamination in the core tube. The pollution prevention device includes a quartz manifold and a quartz flange installed below it. The quartz manifold and the quartz flange are formed in a ring shape having an inclined main surface, and are joined to each inclined main surface, and are formed in a recess formed on one side of the inclined main surface of the quartz manifold and the quartz flange. It is characterized in that the O-ring is fitted.

According to the ultra-high temperature heat treatment apparatus of the present invention, the O-ring is fixed between the quartz manifold and the quartz manifold constituting the pollution prevention device so that the O-ring cannot be detached and the contamination in the core tube is reliably prevented by the pollution prevention device.

In the ultra-high temperature heat treatment apparatus according to another aspect of the present invention, a heat treatment target to be heat-treated in a low-core tube, preferably a porous SiC / CVD-SiC low-core tube, preferably the wafer has an outer diameter larger than the outer diameter of the heat treatment target, and the heat treatment target is fixed. And a separating mechanism for separating from the ring holder. The separating mechanism includes a fixing part for fixing an outer circumferential edge of the ring-shaped holder and an outer diameter that is disposed in conformity with the central axis of the separating mechanism, the outer diameter being higher than the fixing part and smaller than the inner diameter of the ring-shaped holder. It includes.

According to the ultra-high temperature heat treatment apparatus of the present invention, when the ring-shaped holder and the heat treatment target preferably fixed to the wafer are placed on the separating mechanism, the placing holder inserts the center hole of the ring-shaped holder while the ring-shaped holder is placed in the separating mechanism of the separating mechanism. At this height level, the outer rim of the ring-shaped holder is fixed by the fixing portion of the separating mechanism, while the heat treatment object is supported on the upper surface of the stocking die of the separating apparatus. As a result, the heat treatment object is separated from the ring holder. Thus, the heat treatment object and the holder can be separated very simply by placing the heat treatment object and the holder on the separator.

Preferably, the separating mechanism has a housing for supporting the fixing portion, and the fixing portion is formed in a ring shape having an inner diameter smaller than the outer diameter of the holder, and the placing die is a ring-shaped pile which extends radially outward from its lower portion. A die extension portion is provided, wherein the ring-shaped deposition die extension portion is secured by an upper surface of the ring-shaped fixing portion of the separation mechanism.

According to a preferred embodiment of the present invention, when the placing mechanism of the separating mechanism is placed on the ring-shaped fixing portion fixed by the housing of the separating mechanism, the ring-shaped placing die extension part is fixed by the ring-shaped fixing portion at its outer peripheral edge thereof. Is aligned with the central axis of the separation mechanism.

More preferably, the separating mechanism includes a plurality of separating mechanism portions arranged at intervals in the height direction of the housing, each separating mechanism having a ring-shaped fixing portion and a ring-shaped loading die extension portion fixed by the housing. It includes.

According to this preferred embodiment, the ring-shaped gearing die extension portion is placed on the ring-shaped fixing portion of the lowermost separating mechanism portion to position the stocking die, and then the ring-shaped holder and the heat treatment object fixed thereto are placed on the lowering-separating mechanism portion. The object to be heat treated and the holder are separated and fixed by each of the dropping die and the supporting portion of the separation mechanism portion at the bottom. Subsequently, the ring-shaped loading die extension portion is placed on the ring-shaped fixing portion of the second separating mechanism portion from the lower side, and the heat treatment object and the holder can be separated and fixed on the same mechanism portion. By repeating this procedure, a plurality of heat treatment targets, preferably wafers, can be arranged in the separation mechanism at intervals in the height direction.

Furthermore, the structural features of the first to fifth aspects of the present invention and their suitable aspects can be combined in various ways.

1 is a front view showing an ultra-high temperature heat treatment apparatus according to an embodiment of the present invention.

FIG. 2 is a rear view of the heat treatment apparatus shown in FIG. 1. FIG.

Figure 3 is an enlarged front view of a partial incision in the main portion in the heat treatment apparatus.

4 shows a heater element of an electric furnace of the heat treatment apparatus, and FIGS. 4A and 4B show a partial cutaway front view and a right side view of the heater element.

5 is a schematic view of the heat treatment apparatus shown in FIG.

6 is an enlarged longitudinal sectional view of a part of the heat treatment apparatus main portion.

7 is a perspective view of a quartz manifold of a heat treatment apparatus.

8 is a longitudinal front view of a separation mechanism for separating a wafer to be subjected to heat treatment from a holder in a heat treatment apparatus;

9 is a right side view of the separating mechanism shown in FIG. 8;

10 is a plan view of the separation mechanism;

Next, a longitudinal ultra high temperature heat treatment apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

As shown in Figs. 1 to 3, the ultra-high temperature heat treatment apparatus A includes an electric furnace B corresponding to 1,500 ° C constituting the main part thereof. The heater of the electric furnace B consists of the heater elements 1 shown to FIG. 4A and FIG. 4B, These heater elements 1 do not adhere closely to the inner wall surface 3 of the heat insulation material 2 of the electric furnace B. FIG. It is installed in the electric furnace (B) without being replaced at the same time as one unit. Each heater element 1 has a U-shaped heat generating portion 4 as seen from the front as shown in Figs. 4A and 4B, and two attachments extending at right angles, for example, at the base end of the heat generating portion 4. It consists of a part (5).

In the heater device to the electric furnace (B), as shown in Figs. 1 to 3, the attachment portion (5) of the heater element (1) is disposed through the heat insulating material (2) of the electric furnace (B), the heater element (1) The heat generating portion 4 is arranged along the wall surface 3 of the heat insulating material 2 without being in close contact with the inner wall surface 3 of the heat insulating material 2 and not being fixed to the heat insulating material 2. In addition, the attachment part 5 of the heater element 1 is fixed to the outer wall part 2-1 which covers the heat insulating material 2 at predetermined intervals. In detail, the base end which protruded below the outer wall part 2-1 of the attachment part 5 is fixed to the outer wall part 2-1 by the stopper 5-1 and the mesh wire 5-2. In this way, since the heater elements 1 of the heaters are mounted on the heat insulating material 2 independently of each other, one or several damaged heater elements can be replaced by one unit. From this point of view, the heater of this embodiment is remarkably different from the conventional heater structure in which the whole heater has to be replaced when a part of the heater integrally formed is damaged, and the cost of repair work can be significantly reduced. Reference numeral 6 is a gap between the heat generating portion 4 of the heater element 1 and the inner wall surface 3 of the heat insulating material 2.

Moreover, in the electric furnace B, the heat generating part 4 of the heater element 1 of the heater mentioned above is arrange | positioned at the wall surface 3 of the heat insulating material 2 at predetermined intervals, and for this reason, the heat generating part 4 and Unfavorable reaction between the heat insulating materials 2 and shrinkage of the heat insulating materials 2 are suppressed. In addition, the heating operation of the heater is stably performed to a predetermined temperature. In addition, since the heater 4 of the heater element 1 is not mechanically constrained, the heater is less likely to suffer from deterioration in durability due to thermal strain stress, thereby extending its life. In addition, since the heat generating portion 4 of the heater element 1 does not directly contact the heat insulating material 2, the heat loss of the heat generating portion 4 can be reduced.

The number of heater elements 1 constituting the heater can be appropriately changed depending on the size of the electric furnace B, the required performance, and the like.

The heat treatment apparatus A of this embodiment will be described again.

1 to 3 and 5, the heat treatment apparatus A includes a furnace core tube 7 made of porous SiC / CVD-SiC, and a manifold 8 provided below the manifold. 8) is characterized by being made of quartz.

In the conventional heat treatment apparatus, a water-cooled metal manifold is used, and an O-ring or the like is inserted into the junction between the core core 7 and the water-cooled metal manifold to prevent intrusion of contaminants from the outside. For this reason, a low core tube with a long pipe length or crack length was difficult to construct.

On the other hand, in the present embodiment using the quartz indentation holder 8, the junction part of the core tube 7 and the manifold 8 can be arranged in a high temperature environment, thereby making it possible to lengthen the temperature cracking field. Furthermore, the thermal shock to the porous core 7 made of porous SiC / CVD-SiC can be alleviated, and the manufacturing cost of the heat treatment apparatus A can be reduced.

As shown in Figs. 6 and 7, a ring-shaped slit portion 9 is arranged on the upper surface 11 of the quartz manifold 8 joined to the porous SiC / CVD-SiC core core 7 and the slit portion ( The vacuum exhaust path 10 was connected to 9). In addition, the shape dimension of the said slit part 9 is not limited to the thing like drawing.

The reason for arranging the slit portion 9 at the junction between the core core 7 and the manifold 8 is that the O-ring or the like is placed in the junction to deteriorate under a high temperature environment. On the other hand, when the slit portion 9 formed on the upper surface 11 of the manifold 8 is connected to the vacuum exhaust path 10, the lower core 7 is closed by the negative pressure generated in the slit portion 9. ), The joint can be shielded. In addition, the high temperature heat around the junction is discharged. The exhaust path 10 was disposed in the quartz manifold 8 and opened in the core tube 7 made of SiC / CVD-SiC, thereby reducing metal contamination.

The heat treatment apparatus A is provided with a heat insulating apparatus including a SiC buffer 12 and a quartz buffer 13 provided below and fitted in a porous core 7 made of porous SiC / CVD-SiC. This insulator reduces heat conduction to the bottom of the core tube 7 and simplifies cooling of the buffer mounting portion. Therefore, cost reduction was achieved compared with the conventional heat insulating apparatus for porous SiC / CVD-SiC core core tubes which consist only of SiC buffers.

As shown in FIG. 6, the heat treatment apparatus A includes a pollution prevention device installed below the core core 7 made of porous SiC / CVD-SiC to prevent contamination in the core core 7. This pollution prevention device includes the manifold 8 described above and the quartz flange 15 provided below the manifold 8. And the manifold 8 and the flange 15 are formed in ring shape, and have the inclined inner peripheral surface 14 and the inclined outer peripheral surface 16, respectively. The recessed part 17 is arrange | positioned at this inclined outer peripheral surface 16, and the O-ring 18 is fitted so that it may not leave this recessed part 17. FIG. It should be noted that the flange 15 lower than the manifold 8 is not simply inserted between the inclined inner circumferential surface 14 of the manifold 8 and the inclined outer circumferential surface 16 of the flange 15. The O-ring 18 is inserted into the concave portion 17 formed in the c) so that the O-ring 18 does not separate from the manifold 8 and the flange 15. The inclination angles of the inclined circumferential surfaces 14 and 16 are not limited. In addition, the O-ring is because the material is excellent in high temperature heat and durability.

As shown in FIGS. 8 to 10, the heat treatment apparatus A separates the wafer 19 to be heat-treated in the porous core 7 made of porous SiC / CVD-SiC from the ring-shaped holder 20 having an outer diameter larger than that of the wafer 19. Is equipped with a separation mechanism. This separation mechanism has a fixing portion 23 for fixing the outer rim portion 21 of the holder 20, the fixing portion 23 has a plurality of ends so that the holder 20 of various outer diameters can fix the desired one (22) is formed. In addition, the separating mechanism includes an accumulator die 24 which is disposed in conformity with its central axis and has an outer diameter that is higher than the fixing portion 23 and smaller than the inner diameter of the ring-shaped holder 20. Reference numeral 25 denotes a vacuum exhaust passage that sucks the wafer 19.

When the ring holder 20 and the wafer 9 fixed thereto are placed on the separation mechanism, the housing holder 24 is inserted into the center hole of the ring holder 20 while the ring holder 20 is disposed on the housing holder 24. The outer peripheral edge of the ring-shaped holder 20 is fixed by the fixing portion 23 at the height level lower than the upper surface, while the wafer 19 is supported on the upper surface of the loading die 24. . As a result, the wafer 19 is separated from the holder 20. And the wafer 19 supported by the accumulator die 24 is conveyed to a predetermined position via an automatic conveyance apparatus.

Although the heat treatment apparatus A of this embodiment performs heat treatment of a wafer or the like, it can be configured in the form of a vertical vapor deposition apparatus described in Japanese Patent Laid-Open No. 5-86478, which is cited in the present specification. .

In the heat treatment apparatus A used for heat treatment or vapor phase growth, the core tube is vertically mounted above the manifold disposed on the flange as described above, and the heater is arranged around the core tube. The junction between the manifold and the core tube is structured to maintain airtightness.

And a cooling water circulation part is arrange | positioned in the vicinity of a junction part, and cooling water is supplied and circulated to this cooling water circulation part. The manifold is provided with a gas introduction section for introducing a heat treatment atmosphere gas or a gas phase growth process gas into the core tube, and an exhaust port communicating with a vacuum pump for depressurizing and vacuuming the inside of the core tube. Typically, the inside of the core tube is heated by a heater, and the inside of the core tube is reduced by a vacuum pump, and then an atmosphere gas or a process gas is supplied into the core tube. The object to be processed, such as a silicon wafer, is mounted on a board provided above the flange.

In connection with heating, decompression, gas supply, and board transfer of the furnace core tube, the heat treatment apparatus A has the following elements as shown in FIGS. 1 to 3, 4, and 5. Reference numeral 26 denotes a board and a holder made of SiC that rises in the core tube 7, and reference numeral 27 denotes a wool insulating material attachment portion attached to the lower inner side of the heat insulating material 2. Reference numeral 28 is a lock mechanism of the manifold (8), 29 is a gas introduction portion into the furnace, 30 is a board elevator mechanism, 31 is a cooling water inlet, 33 is an internal measurement SiC pipe, and 34 is an exhaust pipe. The reference numeral 35 denotes a furnace inlet quartz shutter unit, reference numeral 36 denotes a board elevator mechanism, reference numeral 37 denotes an external air inlet, reference numeral 38 denotes a cylindrical insulator, and reference numeral 39 denotes an insulator divided into two. Reference numeral 1a denotes a thermocouple for temperature measurement in each zone.

The heater of the electric furnace is composed of a plurality of heater elements arranged to be exchanged independently of each other, each heater element is fixed to the heat insulating portion and the heating portion disposed along the inner wall surface of the heat insulating material and not in close contact with the inner wall surface It has an attachment part. According to this heater structure, the maintenance cost of a heater can be remarkably reduced, reaction of a heat generating part and a furnace material, and reduction of shrinkage of a furnace material can be reduced.

Claims (12)

An electric furnace comprising a heater consisting of a plurality of heater elements arranged to be exchanged independently of each other, each heater element is characterized in that the heater is arranged in close contact with the inner wall surface of the furnace insulation. The method of claim 1, And the heater element has a heat generating portion disposed along the inner wall surface of the heat insulating material and not in close contact with the inner wall surface, and an attachment portion fixed to the heat insulating material. An ultra-high temperature heat treatment apparatus comprising a furnace core tube and a quartz manifold disposed below the furnace core tube. The method of claim 3, wherein Ultra-high temperature heat treatment apparatus characterized in that the core tube is made of porous SiC / CVD-SiC. The method of claim 4, wherein An ultra-high temperature heat treatment apparatus characterized by arranging a slit portion on the quartz manifold upper surface to be joined to the furnace core tube and connecting a vacuum exhaust system to the slit portion. And a heat insulation device inserted into the furnace core pipe to block heat conducted from the furnace core pipe, wherein the heat insulation device includes a SiC buffer and a quartz buffer installed below it. Device. The method of claim 6, Ultra-high temperature heat treatment apparatus characterized in that the core tube is made of porous SiC / CVD-SiC. A furnace core pipe and a pollution prevention device installed below the furnace core pipe to prevent contamination in the furnace core pipe, wherein the pollution prevention device includes a quartz manifold and a quartz flange installed below it. The quartz manifold and the quartz flange are formed in a ring shape having an inclined main surface, and are joined to each inclined main surface so that an O-ring is formed in the recess formed on one side of the inclined main surface of the quartz manifold and the quartz flange. Ultra high temperature heat treatment apparatus, characterized in that sandwiched. The method of claim 8, Ultra-high temperature heat treatment apparatus characterized in that the core tube is made of porous SiC / CVD-SiC. A separation mechanism for separating the heat treatment object to be heat-treated in the core tube from the ring-shaped holder having an outer diameter larger than the outer diameter of the heat treatment object and fixing the heat treatment object, wherein the separation mechanism is a fixing portion for fixing the outer rim of the ring-shaped holder. And a dropping die which is disposed in conformity with the center axis of the separation mechanism and has an outer diameter that is higher than the fixing portion and smaller than the inner diameter of the ring-shaped holder. The method of claim 10, And said core tube is made of porous SiC / CVD-SiC and said heat treatment target is a wafer. An electric furnace including a heater comprising a plurality of heater elements arranged to be exchanged independently of each other; A core tube made of porous SiC / CVD-SiC, An insulation device inserted into the core tube to block heat conducted from the core tube; A pollution prevention device installed below the core tube to prevent contamination in the core tube; A separation mechanism for separating the heat treatment target to be heat-treated in the core tube from the ring-shaped holder having an outer diameter larger than that of the heat treatment target and fixing the heat treatment target, Each said heater element has a heat generating portion disposed along the inner wall surface of said heat insulating material and not in close contact with said inner wall surface, and an attachment portion fixed to said heat insulating material, The heat insulating device includes a buffer made of SiC and a buffer made of quartz installed thereunder, The pollution prevention device includes a quartz manifold installed below the core tube and a quartz flange installed below the core, wherein the quartz manifold and the quartz flange are formed in a ring shape having an inclined main surface. At the same time, the respective joints are joined on the inclined main surface, and the O-ring is fitted to the recess formed in one side of the inclined main surface of the quartz manifold and the quartz flange, A slit portion is arranged on an upper surface of the quartz manifold joined to the furnace core tube, and a vacuum exhaust system is connected to the slit portion, The separating mechanism includes a fixing part for fixing an outer circumferential edge of the ring-shaped holder and an outer diameter that is disposed in conformity with the central axis of the separating mechanism, the outer diameter being higher than the fixing part and smaller than the inner diameter of the ring-shaped holder. Ultra high temperature heat treatment apparatus comprising a.